Another thought, if you're having random and multiple bugs, is to check grounds. I had some problems on my 87, due to disintegration of ground connnections, especially the strap that goes from the rear of the head to the firewall, which looked good but had actually corroded into powder. Some accessories, such as the radio, come with way inadequate grounds (i.e. the dial lights dim when the bass is turned up, etc.) and would welcome a couple of extras. Otherwise, I would just keep shooting the bugs as they arise, rather than bother with a new harness, because some of them are probably going to be downstream from the main harness anyway - in plugs, sub-harnesses, etc.
If you haven't already, you should probably simply go out and unplug and replug, clean and lube every connector you can get your hands on. If you have windshield leaks, this can include those under the dash. An oft-neglected and problematic connector is the one that joins the front light harness to the main harness. It is stuffed into the bulkhead behind the left headlight, and hard to see. It can corrode, and cause light failures.
Finally, if you have a lot of power goodies, you can pretty much expect that the wiring to the doors will fail periodically and need splicing. There was a thread here recently about speaker problems, which indicated that this is a very common problem, especially with the driver's door.
